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Two new coordination polymers, [Zn(2-mBIM)2(NO3)2(H2O)2]n (1) and [Zn(BIM)2(NO3)2(H2O)2]n (2) (2-mBIM = bis(2-methylimidazol-1-yl)methane, BIM = bis(imidazol-1-yl)-methane), were synthesized by the reactions of Zn(NO3)2 with 2-mBIM and BIM ligands. They were characterized by elemental analyses, IR, TGA and X-ray single-crystal diffraction techniques. Each of metal centers in 1 and 2 is coordinated in a slightly distorted tetrahedral geometry by four aromatic nitrogen atoms from four distinct 2-mBIM or BIM ligands, respectively. In compound 1, each pair of neighboring ZnII centers is bridged by two 2-mBIM ligands to form a 16-membered macrometallacyclic structural motif. Each 2-mBIM ligand is coordinated to two ZnII cations and acts as a bridged ligand to form a one-dimensional polymeric cationic chain structure. Compound 2 has a 2D network structure containing 1D channel, thereby each BIM ligand is coordinated to two ZnII cations and thus acts as a bridging ligand. Moreover, each group of four BIM ligands is linked alternatively to each other by four ZnII cations, resulting in a 32-membered macrometallacycle.

A new fluorescent molecule clip derived from diethoxycarbonyl glycoluril with two 2,5-diphenyl-furan sidewalls was designed and synthesized. Its structure and conformation was confirmed by single-crystal X-ray diffraction. Its binding properties, investigated by fluorescence spectroscopey, showed that it can selectively bind Fe3+ with fluorescence quenching.Key words: diethoxycarbonyl glycoluril, molecular clip, fluorescence, Fe(III).

In the title compound, C22H20O5, the substituted benzene rings are twisted away from the furan ring, making dihedral angles of 54.91 (14) and 20.96 (15)° with the furan ring. The dihedral angle between the two benzene rings is 46.89 (13)°. One ethyl group of one ethoxycarbonyl unit is disordered over two sets of sites with occupancies of 0.56 (12) and 0.44 (12). In the crystal, weak intramolecular C—H...O hydrogen bonds link the molecules into chains along the c axis.

The title compound, C25H20N4·4H2O, crystallizes with the organic molecule lying on a twofold rotation axis through the methylene bridge C atom; there are also two water molecules in the asymmetric unit. The crystal structure is stabilized by C—H...O, O—H...O and O—H...N hydrogen bonds, linking the water molecules to each other and to the pyridine N atom.

The crystal structure of the title compound, C28H22N6O5·CHCl3, an important intermediate for molecular tweezers, shows intermolecular hydrogen bonding.

In the crystal structure of the title compound, C22H22O6, the asymmetric unit consists of one half-molecule with the other half generated by a centre of inversion. The crystal packing is stabilized by C—H...O intermolecular interactions.

The title compound, C24H18Br2N4O2·H2O, forms a supramolecular structure via N—H...O, O—H...O and C—H...O hydrogen bonds. In the crystal structure, the water molecule serves as a bifurcated hydrogen-bond acceptor and as a hydrogen-bond donor.